text: Hard to ELI5 that but the long and short is Mexico has a historically short sighted government that only really cared about Mexico City for a couple centuries and failed to utilize it's wealth of natural resources, integrate natives into Western culture or build for the future. They are and have always been highly corrupt and while all governments tend to be that way Mexico had people trying to get Western rich off a third world economy which left pretty much nothing for the people in terms of developed infrastructure. When the industrial revolution hit they fell behind.